A 37-year-old Janesville man who told police he was seeing and hearing demons when he killed his grandmother, faces a lifetime commitment in a mental institution.

Rock County Judge Barbara McCroy accepted a guilty plea from 37-year-old Jamie Beggs Tuesday to a single count of first-degree intentional homicide.

McCrory later found Beggs wasn’t responsible as he was suffering from mental disease or defect at the time of the homicide.

The medical examiner determined 97-year-old Kathleen Beggs died of “sharp-force injury of the neck and manual strangulation”.

Beggs could face a lifetime commitment in a mental institution at his sentencing on January 26th.